#pragma once

/**
 * \file sha1.h
 *
 * \brief SHA-1 cryptographic hash function
 *
 *  Copyright (C) 2006-2013, Brainspark B.V.
 *
 *  This file is part of PolarSSL (http://www.polarssl.org)
 *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
 *
 *  All rights reserved.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#include <string.h>

#ifdef _MSC_VER
#include <basetsd.h>
typedef UINT32 uint32_t;
#else
#include <inttypes.h>
#endif

#define POLARSSL_ERR_SHA1_FILE_IO_ERROR -0x0076 /**< Read/write error in file. */

// Regular implementation
//

/**
 * \brief          SHA-1 context structure
 */
typedef struct
{
	uint32_t total[2];        /*!< number of bytes processed  */
	uint32_t state[5];        /*!< intermediate digest state  */
	unsigned char buffer[64]; /*!< data block being processed */

	unsigned char ipad[64]; /*!< HMAC: inner padding        */
	unsigned char opad[64]; /*!< HMAC: outer padding        */
} sha1_context;

#ifdef __cplusplus
extern "C"
{
#endif

	/**
	 * \brief          SHA-1 context setup
	 *
	 * \param ctx      context to be initialized
	 */
	void sha1_starts(sha1_context* ctx);

	/**
	 * \brief          SHA-1 process buffer
	 *
	 * \param ctx      SHA-1 context
	 * \param input    buffer holding the  data
	 * \param ilen     length of the input data
	 */
	void sha1_update(sha1_context* ctx, const unsigned char* input, size_t ilen);

	/**
	 * \brief          SHA-1 final digest
	 *
	 * \param ctx      SHA-1 context
	 * \param output   SHA-1 checksum result
	 */
	void sha1_finish(sha1_context* ctx, unsigned char output[20]);

	/* Internal use */
	void sha1_process(sha1_context* ctx, const unsigned char data[64]);

#ifdef __cplusplus
}
#endif

#ifdef __cplusplus
extern "C"
{
#endif

	/**
	 * \brief          Output = SHA-1( input buffer )
	 *
	 * \param input    buffer holding the  data
	 * \param ilen     length of the input data
	 * \param output   SHA-1 checksum result
	 */
	void sha1(const unsigned char* input, size_t ilen, unsigned char output[20]);

	/**
	 * \brief          Output = SHA-1( file contents )
	 *
	 * \param path     input file name
	 * \param output   SHA-1 checksum result
	 *
	 * \return         0 if successful, or POLARSSL_ERR_SHA1_FILE_IO_ERROR
	 */
	int sha1_file(const char* path, unsigned char output[20]);

	/**
	 * \brief          SHA-1 HMAC context setup
	 *
	 * \param ctx      HMAC context to be initialized
	 * \param key      HMAC secret key
	 * \param keylen   length of the HMAC key
	 */
	void sha1_hmac_starts(sha1_context* ctx, const unsigned char* key, size_t keylen);

	/**
	 * \brief          SHA-1 HMAC process buffer
	 *
	 * \param ctx      HMAC context
	 * \param input    buffer holding the  data
	 * \param ilen     length of the input data
	 */
	void sha1_hmac_update(sha1_context* ctx, const unsigned char* input, size_t ilen);

	/**
	 * \brief          SHA-1 HMAC final digest
	 *
	 * \param ctx      HMAC context
	 * \param output   SHA-1 HMAC checksum result
	 */
	void sha1_hmac_finish(sha1_context* ctx, unsigned char output[20]);

	/**
	 * \brief          SHA-1 HMAC context reset
	 *
	 * \param ctx      HMAC context to be reset
	 */
	void sha1_hmac_reset(sha1_context* ctx);

	/**
	 * \brief          Output = HMAC-SHA-1( hmac key, input buffer )
	 *
	 * \param key      HMAC secret key
	 * \param keylen   length of the HMAC key
	 * \param input    buffer holding the  data
	 * \param ilen     length of the input data
	 * \param output   HMAC-SHA-1 result
	 */
	void sha1_hmac(const unsigned char* key, size_t keylen,
		const unsigned char* input, size_t ilen,
		unsigned char output[20]);

#ifdef __cplusplus
}
#endif
